Interpretive Summary: Control of adult mosquitoes is based primarily on the use of synthetic chemical pesticides which can lead to insecticide resistance in the mosquito population. In this study, ARS (Gainesville, FL) and Anastasia Mosquito Control District (St. Augustine, FL) scientists evaluated a bait containing boric acid in sugar/water solution that was applied to plant surfaces as a non-chemical control method for adult mosquitoes. In outdoor tests, the baits provided a significant reduction in the number of mosquito that landed on a human subject for 7 days. The results indicate that boric acid bait applied to plant foliage may be a safe and effective alternative control method for adult mosquitoes.

Technical Abstract:
The use of toxic baits to kill adult Aedes albopictus (Skuse) mosquitoes is a safe and potentially effective alternative to the use of synthetic chemical insecticides. This study was made to identify effective application rates for boric acid-sugar solution baits sprayed onto plant surfaces and to characterize the persistence of these baits in terms of a sustained reduction of adult mosquito densities. In outdoor tests in 1100 m3 screened enclosures, landing rates of Ae. albopictus on a human subject and capture rates of female mosquitoes in mechanical traps were significantly reduced using a 1% boric acid bait compared with responses to the 0.25, 0.50, and 0.75% application rates and a negative control. Studies of boric acid bait persistence and activity on plant surfaces were made in 1.4 m3 cages in the laboratory and outdoors in 78 m3 screened enclosures. In the laboratory tests, 1% boric acid bait resulted in >96% mortality in male and female Ae. albopictus for 14 d, whereas in outdoor tests, mosquito landing rates in the treated enclosures were significantly lower than in the control enclosures for 7 d. Mosquito mortality responses to boric acid bait on plant surfaces (1.4 m3 cages in the laboratory) were not affected by the availability of plant inflorescence. The results of this study suggest that boric acid baits applied to plant surfaces may provide an effective point-source-based adjunct/alternative to the use of adulticides for mosquito control.